lib/libcrypto/asn1/asn1_lib.c

   1 /* $OpenBSD: asn1_lib.c,v 1.39 2017/05/02 03:59:44 deraadt Exp $ */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <limits.h>
  60 #include <stdio.h>
  61 #include <string.h>
  62
  63 #include <openssl/asn1.h>
  64 #include <openssl/err.h>
  65
  66 static int asn1_get_length(const unsigned char **pp, int *inf, long *rl, int max);
  67 static void asn1_put_length(unsigned char **pp, int length);
  68
  69 static int
  70 _asn1_check_infinite_end(const unsigned char **p, long len)
  71 {
  72         /* If there is 0 or 1 byte left, the length check should pick
  73          * things up */
  74         if (len <= 0)
  75                 return (1);
  76         else if ((len >= 2) && ((*p)[0] == 0) && ((*p)[1] == 0)) {
  77                 (*p) += 2;
  78                 return (1);
  79         }
  80         return (0);
  81 }
  82
  83 int
  84 ASN1_check_infinite_end(unsigned char **p, long len)
  85 {
  86         return _asn1_check_infinite_end((const unsigned char **)p, len);
  87 }
  88
  89 int
  90 ASN1_const_check_infinite_end(const unsigned char **p, long len)
  91 {
  92         return _asn1_check_infinite_end(p, len);
  93 }
  94
  95 int
  96 ASN1_get_object(const unsigned char **pp, long *plength, int *ptag,
  97     int *pclass, long omax)
  98 {
  99         int i, ret;
 100         long l;
 101         const unsigned char *p= *pp;
 102         int tag, xclass, inf;
 103         long max = omax;
 104
 105         if (!max)
 106                 goto err;
 107         ret = (*p & V_ASN1_CONSTRUCTED);
 108         xclass = (*p & V_ASN1_PRIVATE);
 109         i= *p & V_ASN1_PRIMITIVE_TAG;
 110         if (i == V_ASN1_PRIMITIVE_TAG) {                /* high-tag */
 111                 p++;
 112                 if (--max == 0)
 113                         goto err;
 114                 l = 0;
 115                 while (*p & 0x80) {
 116                         l <<= 7L;
 117                         l |= *(p++) & 0x7f;
 118                         if (--max == 0)
 119                                 goto err;
 120                         if (l > (INT_MAX >> 7L))
 121                                 goto err;
 122                 }
 123                 l <<= 7L;
 124                 l |= *(p++) & 0x7f;
 125                 tag = (int)l;
 126                 if (--max == 0)
 127                         goto err;
 128         } else {
 129                 tag = i;
 130                 p++;
 131                 if (--max == 0)
 132                         goto err;
 133         }
 134         *ptag = tag;
 135         *pclass = xclass;
 136         if (!asn1_get_length(&p, &inf, plength, (int)max))
 137                 goto err;
 138
 139         if (inf && !(ret & V_ASN1_CONSTRUCTED))
 140                 goto err;
 141
 142         if (*plength > (omax - (p - *pp))) {
 143                 ASN1error(ASN1_R_TOO_LONG);
 144                 /* Set this so that even if things are not long enough
 145                  * the values are set correctly */
 146                 ret |= 0x80;
 147         }
 148         *pp = p;
 149         return (ret | inf);
 150
 151 err:
 152         ASN1error(ASN1_R_HEADER_TOO_LONG);
 153         return (0x80);
 154 }
 155
 156 static int
 157 asn1_get_length(const unsigned char **pp, int *inf, long *rl, int max)
 158 {
 159         const unsigned char *p= *pp;
 160         unsigned long ret = 0;
 161         unsigned int i;
 162
 163         if (max-- < 1)
 164                 return (0);
 165         if (*p == 0x80) {
 166                 *inf = 1;
 167                 ret = 0;
 168                 p++;
 169         } else {
 170                 *inf = 0;
 171                 i= *p & 0x7f;
 172                 if (*(p++) & 0x80) {
 173                         if (max < (int)i)
 174                                 return (0);
 175                         /* skip leading zeroes */
 176                         while (i && *p == 0) {
 177                                 p++;
 178                                 i--;
 179                         }
 180                         if (i > sizeof(long))
 181                                 return 0;
 182                         while (i-- > 0) {
 183                                 ret <<= 8L;
 184                                 ret |= *(p++);
 185                         }
 186                 } else
 187                         ret = i;
 188         }
 189         if (ret > LONG_MAX)
 190                 return 0;
 191         *pp = p;
 192         *rl = (long)ret;
 193         return (1);
 194 }
 195
 196 /* class 0 is constructed
 197  * constructed == 2 for indefinite length constructed */
 198 void
 199 ASN1_put_object(unsigned char **pp, int constructed, int length, int tag,
 200     int xclass)
 201 {
 202         unsigned char *p= *pp;
 203         int i, ttag;
 204
 205         i = (constructed) ? V_ASN1_CONSTRUCTED : 0;
 206         i |= (xclass & V_ASN1_PRIVATE);
 207         if (tag < 31)
 208                 *(p++) = i | (tag & V_ASN1_PRIMITIVE_TAG);
 209         else {
 210                 *(p++) = i | V_ASN1_PRIMITIVE_TAG;
 211                 for(i = 0, ttag = tag; ttag > 0; i++)
 212                         ttag >>= 7;
 213                 ttag = i;
 214                 while (i-- > 0) {
 215                         p[i] = tag & 0x7f;
 216                         if (i != (ttag - 1))
 217                                 p[i] |= 0x80;
 218                         tag >>= 7;
 219                 }
 220                 p += ttag;
 221         }
 222         if (constructed == 2)
 223                 *(p++) = 0x80;
 224         else
 225                 asn1_put_length(&p, length);
 226         *pp = p;
 227 }
 228
 229 int
 230 ASN1_put_eoc(unsigned char **pp)
 231 {
 232         unsigned char *p = *pp;
 233
 234         *p++ = 0;
 235         *p++ = 0;
 236         *pp = p;
 237         return 2;
 238 }
 239
 240 static void
 241 asn1_put_length(unsigned char **pp, int length)
 242 {
 243         unsigned char *p= *pp;
 244
 245         int i, l;
 246         if (length <= 127)
 247                 *(p++) = (unsigned char)length;
 248         else {
 249                 l = length;
 250                 for (i = 0; l > 0; i++)
 251                         l >>= 8;
 252                 *(p++) = i | 0x80;
 253                 l = i;
 254                 while (i-- > 0) {
 255                         p[i] = length & 0xff;
 256                         length >>= 8;
 257                 }
 258                 p += l;
 259         }
 260         *pp = p;
 261 }
 262
 263 int
 264 ASN1_object_size(int constructed, int length, int tag)
 265 {
 266         int ret;
 267
 268         ret = length;
 269         ret++;
 270         if (tag >= 31) {
 271                 while (tag > 0) {
 272                         tag >>= 7;
 273                         ret++;
 274                 }
 275         }
 276         if (constructed == 2)
 277                 return ret + 3;
 278         ret++;
 279         if (length > 127) {
 280                 while (length > 0) {
 281                         length >>= 8;
 282                         ret++;
 283                 }
 284         }
 285         return (ret);
 286 }
 287
 288 static int
 289 _asn1_Finish(ASN1_const_CTX *c)
 290 {
 291         if ((c->inf == (1|V_ASN1_CONSTRUCTED)) && (!c->eos)) {
 292                 if (!ASN1_const_check_infinite_end(&c->p, c->slen)) {
 293                         c->error = ERR_R_MISSING_ASN1_EOS;
 294                         return (0);
 295                 }
 296         }
 297         if (((c->slen != 0) && !(c->inf & 1)) ||
 298             ((c->slen < 0) && (c->inf & 1))) {
 299                 c->error = ERR_R_ASN1_LENGTH_MISMATCH;
 300                 return (0);
 301         }
 302         return (1);
 303 }
 304
 305 int
 306 asn1_Finish(ASN1_CTX *c)
 307 {
 308         return _asn1_Finish((ASN1_const_CTX *)c);
 309 }
 310
 311 int
 312 asn1_const_Finish(ASN1_const_CTX *c)
 313 {
 314         return _asn1_Finish(c);
 315 }
 316
 317 int
 318 asn1_GetSequence(ASN1_const_CTX *c, long *length)
 319 {
 320         const unsigned char *q;
 321
 322         q = c->p;
 323         c->inf = ASN1_get_object(&(c->p), &(c->slen), &(c->tag), &(c->xclass),
 324             *length);
 325         if (c->inf & 0x80) {
 326                 c->error = ERR_R_BAD_GET_ASN1_OBJECT_CALL;
 327                 return (0);
 328         }
 329         if (c->tag != V_ASN1_SEQUENCE) {
 330                 c->error = ERR_R_EXPECTING_AN_ASN1_SEQUENCE;
 331                 return (0);
 332         }
 333         (*length) -= (c->p - q);
 334         if (c->max && (*length < 0)) {
 335                 c->error = ERR_R_ASN1_LENGTH_MISMATCH;
 336                 return (0);
 337         }
 338         if (c->inf == (1|V_ASN1_CONSTRUCTED))
 339                 c->slen= *length+ *(c->pp) - c->p;
 340         c->eos = 0;
 341         return (1);
 342 }
 343
 344 int
 345 ASN1_STRING_copy(ASN1_STRING *dst, const ASN1_STRING *str)
 346 {
 347         if (str == NULL)
 348                 return 0;
 349         dst->type = str->type;
 350         if (!ASN1_STRING_set(dst, str->data, str->length))
 351                 return 0;
 352         dst->flags = str->flags;
 353         return 1;
 354 }
 355
 356 ASN1_STRING *
 357 ASN1_STRING_dup(const ASN1_STRING *str)
 358 {
 359         ASN1_STRING *ret;
 360
 361         if (!str)
 362                 return NULL;
 363         ret = ASN1_STRING_new();
 364         if (!ret)
 365                 return NULL;
 366         if (!ASN1_STRING_copy(ret, str)) {
 367                 ASN1_STRING_free(ret);
 368                 return NULL;
 369         }
 370         return ret;
 371 }
 372
 373 int
 374 ASN1_STRING_set(ASN1_STRING *str, const void *_data, int len)
 375 {
 376         const char *data = _data;
 377
 378         if (len < 0) {
 379                 if (data == NULL)
 380                         return (0);
 381                 else
 382                         len = strlen(data);
 383         }
 384         if ((str->length < len) || (str->data == NULL)) {
 385                 unsigned char *tmp;
 386                 tmp = realloc(str->data, len + 1);
 387                 if (tmp == NULL) {
 388                         ASN1error(ERR_R_MALLOC_FAILURE);
 389                         return (0);
 390                 }
 391                 str->data = tmp;
 392         }
 393         str->length = len;
 394         if (data != NULL) {
 395                 memmove(str->data, data, len);
 396         }
 397         str->data[str->length]='\0';
 398         return (1);
 399 }
 400
 401 void
 402 ASN1_STRING_set0(ASN1_STRING *str, void *data, int len)
 403 {
 404         freezero(str->data, str->length);
 405         str->data = data;
 406         str->length = len;
 407 }
 408
 409 ASN1_STRING *
 410 ASN1_STRING_new(void)
 411 {
 412         return (ASN1_STRING_type_new(V_ASN1_OCTET_STRING));
 413 }
 414
 415 ASN1_STRING *
 416 ASN1_STRING_type_new(int type)
 417 {
 418         ASN1_STRING *ret;
 419
 420         ret = malloc(sizeof(ASN1_STRING));
 421         if (ret == NULL) {
 422                 ASN1error(ERR_R_MALLOC_FAILURE);
 423                 return (NULL);
 424         }
 425         ret->length = 0;
 426         ret->type = type;
 427         ret->data = NULL;
 428         ret->flags = 0;
 429         return (ret);
 430 }
 431
 432 void
 433 ASN1_STRING_free(ASN1_STRING *a)
 434 {
 435         if (a == NULL)
 436                 return;
 437         if (a->data != NULL && !(a->flags & ASN1_STRING_FLAG_NDEF))
 438                 freezero(a->data, a->length);
 439         free(a);
 440 }
 441
 442 int
 443 ASN1_STRING_cmp(const ASN1_STRING *a, const ASN1_STRING *b)
 444 {
 445         int i;
 446
 447         i = (a->length - b->length);
 448         if (i == 0) {
 449                 i = memcmp(a->data, b->data, a->length);
 450                 if (i == 0)
 451                         return (a->type - b->type);
 452                 else
 453                         return (i);
 454         } else
 455                 return (i);
 456 }
 457
 458 void
 459 asn1_add_error(const unsigned char *address, int offset)
 460 {
 461         ERR_asprintf_error_data("offset=%d", offset);
 462 }
 463
 464 int
 465 ASN1_STRING_length(const ASN1_STRING *x)
 466 {
 467         return (x->length);
 468 }
 469
 470 void
 471 ASN1_STRING_length_set(ASN1_STRING *x, int len)
 472 {
 473         x->length = len;
 474 }
 475
 476 int
 477 ASN1_STRING_type(ASN1_STRING *x)
 478 {
 479         return (x->type);
 480 }
 481
 482 unsigned char *
 483 ASN1_STRING_data(ASN1_STRING *x)
 484 {
 485         return (x->data);
 486 }